Inside pipe cutter



' Aug. 12, 1930.

H. J. DENNE'Y INS IDE PIPE CUTTER Filed June 1928 Patented Aug; {12, j

INSIDEQPIPE cuisine "I n I Application flled-llliine 1,

This inventionlrelatesto new andfuseful,

improvements inaninside pipe cutter.

One object of the invention is to provide a pipe cutter embodyin a body, havingacyl-' inder therein, with radially movable cutters mounted in bearings in the bodyand aImandrel fitted in said cylinder and operatively I connected with the cutters and operative to project the cutters outwardly into cutting po-v m sition or to withdraw said cutters,'said mandrel being operable in onedirection by a yieldable member to withdraw 'the'cutters and in,

another direction :byfluid pressure beneath the mandrel toactuate the cuttersoutwardly 5 into. cutting relation with the. pipe tobe severed. I

' Anotherobject of the invention is provide', in a pipe'cutter', amandrel, which is fitted in the cylinder of the body and issup- :wzoj ported thereby substantially throughoutiits length.

The cutter isparticularly 'adaptedtobe used for cutting and removing pipe stuck in a well bore. e L With the above and other objects in view the invention has particular relationto certain novel features of construction", operation and arrangement. of parts, an-exam le of which is given in this specification an illus- 1'30 trated in theaccornpanying dra'WingS, whereof thecutter. Figure 2 shows a cross sectional'view taken on the line 22 of Figure 1.

Figure 3 shows a crosslsectional view taken on the line 3-3 ofFigure 1, and

Figure 4 showsa side view of a modified V type of cutter (which may beemployed. Referring now more particularly ,to the drawings, wherein likefnumerals of; reference designate similar parts in each of the figures the numeral -1 designatesthe cutter body, which is tubular'in form, having vthe inside, cylinder 2 with the radiating cutter'bearmgsreceive thecorresponding tenonsflQL.

Figure 1 shows a vertical sectional :view

upper end ofthe body there is" an operating. string :of fpipe fas Fitted in the cylinder, 7 there; is. an} elongated mandrel 5fwhose lower end is fitted-withsuitablecup rings as 6 which within this thimblej there :isthe i' coil spring 8 which is interposed betweenthe'outer 'end of'h the thimbleZ-andtheupperendof the mandrel. The end of the mandrel adjacent the 1 spring carries a :pin 9 which is surroundedrbysaid spring. The mandrel -is limited' in one;direcf-f tio 'n by saidspring and inthe otherjdirection by the inwardly extending'annular flange- 10 1 against which the lowerendpftlie plunger isjadaptedtto abut; i The inandrel hasthe external upwardly; converging-grooves l1 and the-bottomsof these grooveshavethe lengths wise idovetaileda tenons 12 There are the; ra dial cutters 13', in the bearings;;3,whoseinner ends'ehavethe dovetailed cor-tises l l which ,The body has the longitudinal channel'sl5 leading fromtheupperto the lower end there ofand arranged ar'ound the cylinder2k {There ,i Si ajguidekpoint- 16 threaded onto? the "lower end of the body having theinternal chamber,

l7 in which the'channels l5sterminate iThe 7 7 3;, radi'ally disposedtherein; i I

n so; titQcloselyin saidecylinderjand.whiehfform; 1 cin iefiect; aFplunger. screwed i'nto thenppee 7 s end of thecylinderthere isa thimblea l andf r vice may then be removed from the pipe.

As above stated, the mandrel 5 fits closely in the cylinder and is thus supported againstthe lateral strain due to cutting operations so that should one or more of the cutters 13 become broken the remaining cutter will effectively operate against the pipe to be cut. 7 While going intothe bore the fluid in the well will pass inwardly throu h the channels 18 and 20 so as to fill the string 4 thus preventing the string from being crushed by the outside fluid pressure and when withdrawing the device from the bore the fluid in the string 4 will be drained out through said channels 18 and 20. In case the channel20 becomes wornby the grit'and sand in the fluid until it is too large the plug 19may be removed and a newone substituted. The type of cutter designated by the numere! 13 and shown in Figure 4 may beemp'loyed if'desired- This cutter has a side notch 21 and if this type of cutter is used the Yes 11' should have side tenons to be re-1 ceived by said notches 21 to retain the cutters 13' in the bod 1.

As stated t e grooves'converge upwardly and their sides form lateral supports for the cutters thus reinforcing, or strengthening,

' the cutters while inoperation.

cylinder is attached, there being a fluid channel leading from within the string and ter-' minating in said chamber, a yieldable member normally resisting the upward movement of the mandrel and means in the stem attached to the upper end of the cylinder and enclosing said yieldable member and excluding the pressure fluid from the upper end of the mandrel.

In testimony whereof I have signed my name to this specification.

HARVEY JVDENNEY.

While I have shown what I'now consider I I the preferred forms of the invention it is obvious that mechanical chan esmay be made therein and equivalents substituted for the parts shown andI reserve thelright to make such changes and substitutions as may be found desirable within the scope of the appended claims. 7 a i r 'WhatI claim is:-- n

1. A device of the character described including a body having an axial cylinder thereinya mandrel inthe cylinder, cutters mountedin the bod and operatively con-i nected with the man rel, said mandrel being adapted to move said cutters radially as the mandrel is moved longitudinally, said device having a chamber beneath the mandrel, said body having a channel leading from the 7 upper end thereof and terminating in said amber, said chamber having anoutlet ort, a thimble anchored to the upper end 0 the pglygand a yieldable member enclosed by the le normally resisting the upward movement of the mandrel. V 2; A casing cutter having a cylinder and a pressure chamber at one end of the cylinder, a mandrel in the cylinder one end of which is exposedto the pressure of fluid in said chamber, a radially movable cutter opera- 7 tively connected with the mandrel, an operating string t'othe lower end of which the 

